The present invention relates to vehicular audio apparatus for installation on vehicles, such as automotive vehicles, and tone generating methods and programs therefor.
Today, as vehicular audio apparatus for installation on automotive vehicles, apparatus are in practical use which are constructed to produce or audibly output sounds or tones periodically while a direction indicator (also referred to as “winker” or “flasher”) is in operation. There have also been proposed, for example in Japanese Patent Application No. HEI-7-32948, vehicular audio apparatus which detect a degree of opening of a throttle valve responsive to operation of an accelerator pedal and a traveling speed of the vehicle and audibly output sounds or tones in accordance with the detected results. With these conventionally-known vehicular audio apparatus, a human vehicle operator or driver can perceive or recognize, from the audibly-output tones, his or her driving operation and states of the vehicle, such as operation of the direction indicator or winker (flasher), degree of opening of the accelerator and traveling speed of the vehicle, without having to view a gauze board or instrument panel.
However, the tones produced by the above-discussed audio apparatus for allowing the human vehicle driver to recognize his or her driving operation and states of the vehicle tend to be very monotonous, because they are generally fixed tones output periodically in a fixed manner. In addition, these tones are output independently between various types of driving operation and states of the vehicle, which would unavoidably result in very poor harmony between the tones audibly output for the various types of operation and states. As a consequence, in the case where a plurality of tones, representative of driving operation and states of the vehicle, are audibly output at a given time, a combination of these tones tends to sound considerably “mechanical” and give the human vehicle driver and other passenger an uncomfortable feeling.